How do I solve this circuit using superposition and Ohm's law?

In summary, theCircuit has been attached and the student is trying to solve it using superposition. They are confused by the symbol for an ideal current source and need help understanding the difference between the two.
  • #1
Yasmeen073
4
0

Homework Statement



hello Everyone, I've attached the Circuit to this post. We are suppose to solve it using superposition. we are suppose to find the current through the 9 ohm resistor.

Homework Equations



Some relevant equations I thought were the basic ones to solve circuits, for example: Ohm's law, which stats V=IR

The Attempt at a Solution



The thing that is throwing me off with this particular question is that there is a circle thing that has 5A, with an arrow going up. I have NO idea what that arow means, I even googled. The way I thought we would solve this would be to find the Rseries, so would I just add up all the resistances to find that? i.e would I add 4+6=10, then i'd do 1/10 +1/9 (because they are parallel) and then inverse it to equal 4.74, which we would then add to 3, and then do 1/7.74+1/20 (because they are parallel) to obtain 5.58 as a final resistance? I know that superposition means we have to answer the question from both sides. But i don't understand how we solve it from the side of the 5A.

for the 10V part, do we just do V=IR and then do 10V= 5.58I so obtain I=1.79?

thanks for the help!
 

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  • #2
The "circle thing" is a constant current power supply and the arrow gives the direction of the current.
 
  • #3
ooh ok...so is my work correct then?
 
  • #4
By using current nodes and voltage loops, superposition is utilized. Finding the equivalent resistance of the circuit is not using superposition. Keep in mind the constant current source and constant voltage source when using node analysis and voltage loops.
 
  • #5
There is a convenient way to solve this problem using Norton and/or Thevinin equivalents (a total of two), and then using superposition.

BTW, that circle with the + and - and the arrow next to it is NOT the symbol that is typically used for an ideal current source. The ideal current source is typically a circle with an arrow inside, and the ideal voltage source is typically a circle with a + and -. However, the arrow next to the circle would suggest that this is supposed to be an ideal current source, OR that they have given you the resulting current but expect you to treat it as a voltage source - THERE IS A DIFFERENCE.
 
  • #6
wow thanks so much for your help. is it ok if i post my entire solution down? this person help me do it but i feel like it's such a complex way and there are wayy too many steps, could anyone possibly tell me if i could do this in a more simple way? i feel like 3 pages of work is too much for this problem :S
 

1. What is superposition and how does it apply to circuits?

Superposition is a principle in physics that states that in a linear system, the total response to multiple inputs is the sum of the individual responses. In circuit analysis, this means that the voltage or current at any point in a circuit is equal to the sum of the voltage or current caused by each individual source in the circuit.

2. How do you calculate the total response in a circuit using superposition?

To calculate the total response in a circuit using superposition, you must first turn off all but one source in the circuit and calculate the response caused by that source alone. Then, turn off that source and repeat the process for each remaining source in the circuit. Finally, add all of the individual responses together to find the total response.

3. Can superposition be applied to non-linear circuits?

No, superposition only applies to linear circuits, meaning that the relationship between voltage and current in the circuit is proportional. Non-linear components, such as diodes and transistors, do not follow this relationship and therefore cannot be analyzed using superposition.

4. Are there any limitations to using superposition in circuit analysis?

Yes, superposition can only be used in circuits that are in steady-state, meaning that all capacitors have been fully charged and all inductors have reached their maximum potential. Additionally, superposition only applies to circuits with independent sources, meaning that the sources do not depend on each other for their values.

5. How is superposition used in practical applications?

Superposition is a useful tool for analyzing complex circuits and predicting how they will behave. It is commonly used in the design and troubleshooting of electronic devices, such as computers and cell phones. By breaking a circuit down into smaller parts, superposition allows engineers to more easily understand and manipulate its behavior.

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